Fluid flow meters are used to measure the volume of fluid flowing through a system. Water meters, for example, are used in residential and commercial environments to measure the amount of water being supplied by a public water utility.
A diverse spectrum of water metering technologies is being used today to meter water flow. One exemplarily technology is positive displacement water meters. Such technology may use oscillating pistons in communication with register technology that registers the volume of fluid flow by counting the number of times a chamber of a known volume is filled with water and emptied.
For positive displacement meters, water enters one side of the meter housing and flows into a measuring chamber to the flow measuring elements comprising a movable piston (e.g. rotating piston, oscillating piston, etc.). Due to a higher pressure at the input of the meter, water is pushed through the meter causing the movable piston to move resulting a reciprocating motion that forces a second compartment to be emptied as a first compartment is filled. With each movement of the piston the same volume of water enters and leaves the measuring chamber.
A magnetic element is typically associated with such piston to generate a varying magnetic field (varying in that the magnetic field is moving relative to a sensor) that is detected by register components. Importantly, to go from no flow to flow, or to measure ultralow flow, the moving water must have enough energy to start and maintain piston movement; otherwise piston movement stops and such flow is not metered.
To install the flow measuring elements in such a meter, the meter housing is associated with a removable cover or plate. Prior art meters use bolts (typically 4 bolts) to generate the pressure needed to associate the cover to the meter housing. Using bolts not only increases assembly time and the meter's part count, using the typical four bolt configuration to associate the meter plate to the meter base results in an uneven pressure across the meter base and internal components, such as the measurement chamber which will reduce meter accuracy over time due to at least distortion of the measurement chamber.
Embodiments of the present inventions better distribute the pressure used to mechanically associate the meter plate to the meter base resulting in better accuracy over a longer period of time to create a “Perpetual™ meter”. Such embodiments also lower a meter's part count and simplify meter assembly by eliminating the use of bolts for associating a cover to such meter's housing.
Another area where prior residential water meters can be improved relates to ultralow flow conditions. According to one article on ultralow flow, (Richards, G. L., Johnson, M. C., Barfuss, S. L., “Apparent Losses Caused by Water Meter Inaccuracies at Ultralow Flows”, Journal AWWA, 120(5), 123-132 (2010), approximately 16% of all domestic water consumption occurs at flow rates of less than one gallon per minute. Notably, most water meters are required to meet AWWA standards for flow meters and such AWWA standards do not require any degree of meter accuracy below the minimum test flow rates (i.e. at ultralow flow rates). Thus, at just above ultralow flow rates, prior art water meter accuracy drops off rapidly. On reason, at ultralow flow rates, the water often does not have enough inertial energy to start a stopped piston or maintain movement of a prior art piston. Under such conditions the ultralow flow of water will not be metered. Basically, such prior art water meters allow water to flow through the meter at rates below the measurement capabilities of the meter resulting in unmetered flow.
Embodiments of the disclosed inventions relate to configuring a water meter so that flow rates below the meter's measurement capabilities are prevented.
Another issue with prior art meters with movable parts in the measurement chamber is noise. At certain flow rates the moving parts of the measurement components (e.g. measurement chamber) “chatter” and can make a noise loud enough to be annoying. Embodiments of the present invention address such issues.
Still another area where water meters can be improved relates to their Automatic meter reading technology. As noted above, a diverse spectrum of water metering technologies is being used today to meter water flow. Additionally, many such meters are configured with transmitters and radios for transmitting consumption data to Automatic Meter Reading systems. Annoyingly, ARM system manufacturers use their own communication signal protocols and signal configuration to configure the transmitted signal requiring a different receiver configuration for different types of AMR transmitters.
Embodiments of the disclosed technology seek to address the problem of collecting consumption data from multiple types of wireless endpoints (e.g. utility meter) that use different and often proprietary protocols.
Notably, RF transmissions from utility metering devices occur in urban and rural settings and are each designed by their manufacturer to be read by specific and often proprietary equipment. Such can limit market of the user of such equipment, (i.e. a municipality, a coop, a utility district, a private utility provider, etc.), for future upgrades. While it is often times required to entertain multiple bids, and accept low bids, utilities with existing AMR systems may be restricted by the radio equipment already owned, and to limit bids that only include the provider of the original equipment thereby circumventing the fair bidding process. Consequently, the Water Research Foundation in conjunction with AWWA has found that Utilities are finding it difficult to change to another technology when a change is needed, and that no standard for AMR and AMI devices and related software systems exists.
Embodiments of the current novel invention seeks to solve this dilemma by providing a means to read at least the consumption and serial number data from many different utility RF systems regardless of hardware or protocol differences. The disclosed technology will automatically detect AMR and AMI broadcasts by utilizing known parameters, and then going through an algorithm that includes a series of RF parameter detection, signal characterization, signal decoding, and data qualifying techniques with minimal involvement of the user.